Some say the problem is our education system. Schools and colleges should be doing more to encourage girls and young women to explore computing. Right now that's not happening. Overall enrollment in university computer science programs is up 10 percent from last year, but enrollment among women is down.

Others say companies should provide the encouragement. Some companies already are; Etsy, for example, is offering $50,000 in grants to send women to its Hacker School training program in New York City this summer.

That's admirable, but it falls short of addressing the real problem, which is that software development isn't just failing to attract women. It's actively pushing them away. Worse, they're not the only ones.

No girls allowedThere are women who have a genuine passion for programming to rival any man. But even if they manage to get hired over their male counterparts, they often find themselves in hostile, male-dominated work environments.

"As the woman, I've been the only person in the group asked to put together a potluck," writes Katie Cunningham, a Python developer at Cox Media Group. "I've been the only one asked to take notes in a meeting, even if I'm the one who's presenting. I once had a boss who wanted to turn me into a personal assistant so badly, it ended up in a meeting with HR."

Just as harmful, she says, were the casual jokes and comments from her male coworkers. If she didn't shrug them off with a smile, she was told she had a bad attitude. Cunningham says the subtle sexism she encountered as a programmer was so discouraging that she once considered leaving the field for good. "I almost prefer outright sexism, because at least that you can point out," she writes.

These problems certainly aren't limited to programming. Women in all sorts of fields face similar discrimination. But the software development field's hostility toward women may be symptomatic of a broader malady.

No dads, eitherConsider the perennial issue of age discrimination in tech. Programming jobs may favor men, but not all men.